/*
 * jPOS Project [http://jpos.org]
 * Copyright (C) 2000-2015 Alejandro P. Revilla
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

package org.jpos.iso;

/**
 * EBCDIC version of IFB_LLLNUM
 * Uses a 2 EBCDIC byte length field
 *
 * @author julien.moebs@paybox.net
 * @version $Id$
 * @see ISOFieldPackager
 * @see ISOComponent
 */


public class IFEB_LLLNUM extends ISOFieldPackager {
	public IFEB_LLLNUM() {
		super();
	}

	/**
	 * @param len         - field len
	 * @param description symbolic descrption
	 */
	public IFEB_LLLNUM(int len, String description) {
		super(len, description);
	}

	/**
	 * @param c - a component
	 * @return packed component
	 * @throws ISOException
	 */
	public byte[] pack(ISOComponent c) throws ISOException {
		boolean odd = false;
		int len;
		String s = (String) c.getValue();


		if ((len = s.length()) > getLength() || len > 99)   // paranoia settings
			throw new ISOException(
					"invalid len " + len + " packing IFEB_LLLNUM field " + c.getKey());


		//System.out.println("String s = (String) c.getValue(); "+s);


		// if odd length
		if (len % 2 == 1) {
			odd = true;
			len = len / 2 + 1;
		} else {
			odd = false;
			len = len / 2;
		}

		//System.out.println("len= "+ len +" s.length()= "+len);

		String fieldLength = ISOUtil.zeropad(Integer.toString(len), 3);

		byte[] EBCDIClength = ISOUtil.asciiToEbcdic(fieldLength);

		// bcd stuff
		byte[] bcd = ISOUtil.str2bcd(s, false);
		if (odd)
			bcd[len - 1] = (byte) (bcd[len - 1] | 0xf);


		//System.out.println("bcd2str "+ISOUtil.bcd2str(bcd, 0, bcd.length*2, false) );

		byte[] b = new byte[bcd.length + 3];

		b[0] = EBCDIClength[0];
		b[1] = EBCDIClength[1];
		b[2] = EBCDIClength[2];
		System.arraycopy(bcd, 0, b, 3, bcd.length);

		return b;
	}

	/**
	 * @param c      - the Component to unpack
	 * @param b      - binary image
	 * @param offset - starting offset within the binary image
	 * @return consumed bytes
	 * @throws ISOException
	 */
	public int unpack(ISOComponent c, byte[] b, int offset)
			throws ISOException {
		boolean pad = false;


		int len = (b[offset] & 0x0f) * 100 + (b[offset + 1] & 0x0f) * 10 + (b[offset + 2] & 0x0f);

		int tempLen = len * 2;

		//System.out.println("len "+ len +"len*2 "+tempLen);


		// odd handling
		byte testByte = b[offset + 3 + len - 1];

		if ((testByte | 0xf0) == 0xff) {
			// odd length
			tempLen--;
		}


		// bcd line
		//System.out.println("ISOUtil.bcd2str(b, offset+2, len, pad) "+ISOUtil.bcd2str(b, offset+2, tempLen, pad));

		c.setValue(ISOUtil.bcd2str(b, offset + 3, tempLen, pad));

		//c.setValue(ISOUtil.ebcdicToAscii(b, offset+2, len));

		return len + 3;
	}

	public int getMaxPackedLength() {
		return getLength() + 3;
	}
}
